Sofa dermatitis: Value of patch test with 2-(thiocyanomethylthio)benzothiazole.

2-(Thiocyanomethylthio)benzothiazole (TCMTB) is probably an underestimated allergen present in leather chairs (responsible for the so-called 'sofa dermatitis'), and more generally in leather objects. It is, therefore, important to test with TCMTB 0.1% petrolatum in case of contact dermatitis related with leather products.